NEC PD78P214 Manuale Utente
117
Chapter 7 Timer/Counter Units
7
7.1.5 Compare Register and Capture Register Operations
(1) Compare operation
The 16-bit timer/counter performs an operation to compare the values set in the compare registers with timer
count values.
count values.
When the values set in the compare registers (CR00, CR01) coincide with count values of 16-bit timer 0 (TM0),
the coincidence signal is sent to the output control circuit. At the same time, the interrupt requests (INTC00,
INTC01) are generated.
the coincidence signal is sent to the output control circuit. At the same time, the interrupt requests (INTC00,
INTC01) are generated.
After the value of the CR01 register coincides with a count value of TM0, the count value of TM0 can be cleared.
Thus, the 16-bit timer/counter can operate as an interval timer for repeatedly counting up to the value set in
the CR01 register.
Thus, the 16-bit timer/counter can operate as an interval timer for repeatedly counting up to the value set in
the CR01 register.
Caution Before the 16-bit timer/counter can perform a compare operation, a value must be loaded into the compare register or
registers used.
Fig. 7-9 Compare Operation
Remark CLR01 = 0
Coincidence
Coincidence
Coincidence
Coincidence
TM0
count value
count value
Count starts
INTC00
interrupt request
INTC01
interrupt request
OVF0
0H
Cleared by software
FFFFH
CE0
←1
FFFFH
Value of CR01
Value of CR00
Value of CR01
Value of CR00